Display shows Sn2 or SN2; spa may shut down or show incorrect water temperature.

Safety: Turn off power at the GFCI before servicing sensors.

• Step 1 – Locate sensor: Find the secondary/high-limit sensor on the heater manifold or in the plumbing near the heater.
• Step 2 – Inspect wiring: Check the cable for cuts, abrasions, or melted insulation. Repair or replace if damaged.
• Step 3 – Clean and reseat connector: Unplug the sensor from the control pack, inspect for corrosion, clean if necessary, and reconnect firmly.
• Step 4 – Test sensor: Measure resistance and compare to the Vita Spa spec chart. Replace the sensor if readings are out of range.
• Step 5 – Board diagnosis: If a new sensor does not resolve Sn2, the control board’s sensor circuit may be faulty and require professional replacement.